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Skip to next/previous keyframe

Posted: 12 Feb 2009 23:44
by nepthar
I propose a feature where a user could assign a hot key to skip to next or previous keyframe. I'm generally not that picky about seeking accuracy, but I used to use virtualDub and it had a feature similar to this. Perhaps this hotkey would repeat after 1/4 of a second or so, so you could just hold it down and it would continue skipping to the next keyframe.

Anyway, I think this would clear up the issue where you seek to a time between keyframes and have to wait for the next keyframe for the video to display correctly.

Also, I could have sworn VLC already had this feature. I just checked for it (running osx version) and couldn't find it, so if I'm just missing it, please let me know.

-n

Re: Skip to next/previous keyframe

Posted: 13 Feb 2009 00:48
by Jean-Baptiste Kempf
'e' in VLC 1.0

Re: Skip to next/previous keyframe

Posted: 02 Jun 2011 03:51
by DrHow
'e' in VLC 1.0
Incorrect. "e" advances to the next video frame, not to the next keyframe.

I was looking for the same thing, and a search on "vlc next-keyframe" turned up this two year old exchange. I am surprised that the error has never been corrected. As far as I can tell, VLC does not have the feature.

The reason I was hoping for the "next keyframe" feature is that I have a hotkey set up for a 6 second jump ahead. It often does not work; and the symptom of not working is that it actually jumps backwards. I suppose that the reason for this is that the last keyframe before 6 seconds from now can actually be before now. The same problem can arise with the scroll wheel navigation. For a small jump forward, I would be willing to compromise on jumping to the next keyframe, and I have seen players that have this feature. It should not be difficult to provide it in VLC.

Re: Skip to next/previous keyframe

Posted: 02 Jun 2011 15:33
by VLC_help
Jump to next key frame is hard to implement with certain files, and streams (it would require full indexing).

Non-working jumps are usually because VLC demuxer doesn't handle the file correctly or because the file is damaged/corrupted.

Re: Skip to next/previous keyframe

Posted: 04 Jun 2011 02:30
by DrHow
Jump to next key frame is hard to implement with certain files, and streams (it would require full indexing).
OK. But this is not a good reason for failing to implement it with those files for which it is not hard. The type of file on which I most frequently experience the symptom is .mkv encoded with H264, and it was on such a file that I successfully used the feature in another player.
Non-working jumps are usually because VLC demuxer doesn't handle the file correctly or because the file is damaged/corrupted.
The backwards jump symptom occurs very frequently for me, and there is no indication that the files are damaged. At first I thought it might result from streaming rared files over my LAN. But that was not the case. I can extract the complete video file, copy it to the playback machine, and the problem still arises.

Re: Skip to next/previous keyframe

Posted: 04 Jun 2011 13:11
by VLC_help
But this is not a good reason for failing to implement it with those files for which it is not hard.
There are already multiple threads about jump to next frame not working, so if something doesn't work as expected with every file/stream, people will complain.
The backwards jump symptom occurs very frequently for me, and there is no indication that the files are damaged.
Did you test VLC 1.2.0 nightly builds? (they should have somewhat better MKV demuxer)